The present invention relates to a remote diagnosis system for a numerical control apparatus which is capable of diagnosing the operation state of the numerical control apparatus by means of a terminal unit disposed away from the numerical control apparatus through communication between the numerical control apparatus and the terminal unit.
FIG.1 is a block diagram showing an embodiment of a conventional remote diagnosis system for a numerical control apparatus. In a numerical control apparatus (CNC) 1, a CPU 11 reads and analyzes data stored in a data memory 13 in accordance with a program stored in a program memory 12. On the basis of the analyzed result, the CPU 11 controls the delivery of data between an operation panel control section 14 and a machine control section interface 15. A page operation command SA, which is inputted by an operator through a keyboard 22 on an operation panel 2 belonging to the CNC 1, is read in to be analyzed by the operation panel control section 14 in the CNC 1 through a synthesizing circuit 39 disposed in a diagnosis data transmission unit 3. From the analyzed result, image data SB in accordance with the operation state of the CNC 1 are prepared to be displayed on a CRT 21 in the operation panel 2 through a distributor 38 disposed in the diagnosis data transmission unit 3. In the diagnosis data transmission unit 3 belonging to the CNC 1, a CPU 31 reads and analyzes data stored in a data memory 33 in accordance with a program stored in a program memory 39. On the basis of the analyzed result, the CPU 31 controls communication and delivery of data between a page operation means 34, an image storage means 36, a communication means 37, the distributor 38 and the synthesizing circuit 39.
In the terminal unit 4 at a long distance from the CNC 1, a CPU 41 reads and analyzes data stored in a data memory 43 in accordance with a program stored in a program memory 42. On the basis of the analyzed result, the CPU 41 controls delivery of data between an image storage means 44, a communication means 46, a CRT 47 and a keyboard 48. Subsequently, a page operation command SA', which is inputted by the operator through the keyboard 48, is read in by the communication means 46, to thereby be transmitted through a telephone line TL to the communication means 37 in the diagnosis data transmission unit 3. The page operation command SA' accepted by the communication means 37 is sent out to the page operation means 34, to furthermore be transmitted through the synthesizing circuit 39 to the operation panel control section 14 in the CNC 1. In this operation panel control section 14, page-changeover is conducted based on the transmitted page operation command SA', and image data SB for the page are prepared to be stored through the distributor 38 to the image storage means 36 installed. The image data SB which have been stored in the image storage means 36 are, in turn, read in by the communication means 37 in which the data are data-compressed to be transmitted through the telephone line TL to the communication means 46 in the terminal unit 4. In the terminal unit 4, the compressed data is transformed into the original state and stored into the image storage means 44. The image data SB stored in the image storage means 44 is adapted to be transmitted to the CRT 47 to be displayed.
In the conventional remote diagnosis system in the numerical control apparatus described above, since the image data are used as the diagnosis data for the numerical control apparatus, the amount of data to be transmitted becomes markedly large, thus making it impossible to quickly send the data to the terminal unit, to thereby result disadvantageously in a large cost for the communication. As a result, the use of the telephone line is impractical so that it has been indispensable to engage a digital network and so on. Moreover, since the image data constitutes image information, it has been impossible to additionally provide for the terminal a multi-processing function and the like which make it possible to treat the image data as significant information. Accordingly, it is desirable to use character code data as the diagnosis data in place of the image data; however, the character code data stays in the operation panel control section 14 as internal signals. Hence, in order to take out the character code data, the CNC 1 itself is required to be remodeled and incorporated into the diagnosis system to be a CNC-incorporated system. Such an incorporated system no longer has any merits which have been provided by a diagnosis system that does not depends upon the operation of the CNC 1. In addition, when the character code data are taken out from the operation panel control section 14, this disadvantageously makes it impossible for the image data to be transmitted.